Recently, Wanhua Chemical released the environmental impact assessment report (for public consultation) of its 20,000-ton/year polydimethylsiloxane (PDMS) capacity expansion project. The company intends to add two new production lines based on the existing PDMS plant in Yantai Chemical Industry Park, while adjusting the capacity of the existing production lines. Ultimately, the annual capacity of the PDMS plant will be expanded from 9,000 tons to 29,000 tons. 

PDMS has excellent chemical resistance, water resistance, etc., and can be used as defoamers, release agents, additives for paints and daily chemicals. By adding PDMS monomers during the synthesis of polycarbonate (PC) resin for copolymerization, PC-siloxane copolymers (silicon-modified PC) can be formed. These copolymers not only have good flame retardancy but also exhibit excellent fluidity and low-temperature toughness, showing promising prospects in hot fields such as smartphones and new energy vehicles. 

It is reported that in April 2022, Wanhua Chemical′s special silicon-modified PC copolymer project was put into operation, marking the official launch of China′s first high-silicon-content (20%) siloxane PC product. Wanhua Chemical has also become the world′s only supplier of high-silicon-content silicon-modified PC with a complete industrial chain. At present, domestic silicon-modified PC still has a high degree of import dependence. The main foreign manufacturers of silicon-modified PC include Idemitsu Kosan of Japan, Teijin of Japan, etc. In China, in 2017, Gansu Yinguang Chemical Industry Group completed the first domestic silicon-modified PC production plant and operated it stably; in November 2024, Cangzhou Dahua carried out feed testing for 20% silicon-content copolymer PC.